The last game I ran of this involved a post apocalyptic Earth within a shattered Britain and involved an Arthurion-like quest involving Historia Rodentia as extra races available eventually revealing humanity had all been wiped except on Ritia with the anima (Historia Rodentia) being the main species on the continent (Europe).

Something like Glorantha would have oodles of Common magic being, well, common.

Merrie England has a little bit of Common magic available through the main religions and cults, a little bit through Pilgrimages, some through guilds and organisations and some through other means. However, people might have one spell or maybe two.

Something set in the time of the Golden Horde would have Common magic through shamanic cults and through other religions, but that's about it.

Something set in Napoleonic Times would have no Common magic as such, but might have special abilities represented by Common magic effects.